In spring, dust storms raise up a large amount of mineral dust in the atmosphere, which is known as the Asian dust or Kosa in East Asia. The Taklimakan desert and Gobi desert are considered as important sources of the Asian Dust. The Asian dust, if lifted up to the free troposphere, can be transported long distances and affect the global scale. Satellite imagery does not provide information on the aerosol's height distribution. One of the most important parameters which are crucial to the understanding of aerosol transport is the vertical structure of the Asian dust over the source regions. The Japan-China Joint Studies on Origin and Transport of Aeolian Dust and its Impact on Climate (ADEC) has started since 2000. The purpose of ADEC is to figure out the mechanism of mineral dust outbreaks from arid regions into the atmosphere and to evaluate its annual variability. As a part of ADEC, a newly developed lidar has been operated since 2001 at the Aksu oasis (40 37$B!G(JN, 80 50$B!G(JE, 1028 m above the sea level) in the northern fringe of the Taklimakan Desert, Xinjiang, China. The lidar is a Nd:YAG depolarization lidar designed to measure the vertical profiles of backscatter and the depolarization of the aerosol particles from near the ground and up to the stratospheric aerosol layer. The present paper shows the vertical structure of the dust layer and high- and middle-level clouds over the Taklamakan Desert, using the lidar observations at Aksu during the spring of 2002 - 2004